xuartns550_options.c

powerpc405下linux的串口驱动程序

/* $Id: xuartns550_options.c,v 1.2 2006/08/09 05:42:11 mta Exp $ */
/*****************************************************************************
*
*       XILINX IS PROVIDING THIS DESIGN, CODE, OR INFORMATION "AS IS"
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*       INFRINGEMENT, IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
*       FOR A PARTICULAR PURPOSE.
*
*       (c) Copyright 2002 Xilinx Inc.
*       All rights reserved.
*
*****************************************************************************/
/****************************************************************************/
/**
*
* @file xuartns550_options.c
*
* The implementation of the options functions for the XUartNs550 driver.
*
* <pre>
* MODIFICATION HISTORY:
*
* Ver   Who  Date     Changes
* ----- ---- -------- -----------------------------------------------
* 1.00b jhl  03/11/02 Repartitioned driver for smaller files.
* 1.00b rpm  04/12/05 Added critical section protection in ReadFcrRegister
* </pre>
*
*****************************************************************************/

/***************************** Include Files ********************************/

#include "xuartns550.h"
#include "xuartns550_i.h"
#include "xio.h"

/************************** Constant Definitions ****************************/

/**************************** Type Definitions ******************************/

/***************** Macros (Inline Functions) Definitions ********************/

/************************** Variable Definitions ****************************/
/*
 * The following data type maps an option to a register and the bits of the
 * regiser such that getting and setting the options may be table driven.
 */
typedef struct
{
    Xuint16 Option;
    Xuint16 RegisterOffset;
    Xuint8  Mask;
} Mapping;

/*
 * Create the table which contains options which are to be processed to get/set
 * the options. These options are table driven to allow easy maintenance and
 * expansion of the options.
 */

static Mapping OptionsTable[] =
{
    { XUN_OPTION_SET_BREAK,     XUN_LCR_OFFSET,   XUN_LCR_SET_BREAK    },
    { XUN_OPTION_LOOPBACK,      XUN_MCR_OFFSET,  XUN_MCR_LOOP         },
    { XUN_OPTION_DATA_INTR,     XUN_IER_OFFSET,     XUN_IER_RX_DATA      },
    { XUN_OPTION_MODEM_INTR,    XUN_IER_OFFSET,     XUN_IER_MODEM_STATUS },
    { XUN_OPTION_FIFOS_ENABLE,  XUN_FCR_OFFSET,   XUN_FIFO_ENABLE      },
    { XUN_OPTION_RESET_TX_FIFO, XUN_FCR_OFFSET,   XUN_FIFO_TX_RESET    },
    { XUN_OPTION_RESET_RX_FIFO, XUN_FCR_OFFSET,   XUN_FIFO_RX_RESET    },
    { XUN_OPTION_ASSERT_OUT2,   XUN_MCR_OFFSET,  XUN_MCR_OUT_2        },
    { XUN_OPTION_ASSERT_OUT1,   XUN_MCR_OFFSET,  XUN_MCR_OUT_1        },
    { XUN_OPTION_ASSERT_RTS,    XUN_MCR_OFFSET,  XUN_MCR_RTS          },
    { XUN_OPTION_ASSERT_DTR,    XUN_MCR_OFFSET,  XUN_MCR_DTR          }
};

/* Create a constants for the number of entries in the table */

#define XUN_NUM_OPTIONS      (sizeof(OptionsTable) / sizeof(Mapping))

/************************** Function Prototypes *****************************/

static Xuint8 ReadFcrRegister(Xuint32 BaseAddress);

/****************************************************************************/
/**
*
* Gets the options for the specified driver instance. The options are
* implemented as bit masks such that multiple options may be enabled or
* disabled simulataneously.
*
* @param    InstancePtr is a pointer to the XUartNs550 instance to be worked on.
*
* @return
*
* The current options for the UART. The optionss are bit masks that are
* contained in the file xuartns550.h and named XUN_OPTION_*.
*
* @return
*
* None.
*
*****************************************************************************/
Xuint16 XUartNs550_GetOptions(XUartNs550 *InstancePtr)
{
    Xuint16 Options = 0;
    Xuint8 Register;
    Xuint32 Index;

    /*
     * Assert validates the input arguments
     */
    XASSERT_NONVOID(InstancePtr != XNULL);
    XASSERT_NONVOID(InstancePtr->IsReady == XCOMPONENT_IS_READY);

    /*
     * Loop thru the options table to map the physical options in the
     * registers of the UART to the logical options to be returned
     */
    for (Index = 0; Index < XUN_NUM_OPTIONS; Index++)
    {
        /* If the FIFO control register is being read, the make sure to
         * setup the line control register so it can be read
         */
        if (OptionsTable[Index].RegisterOffset == XUN_FCR_OFFSET)
        {
            Register = ReadFcrRegister(InstancePtr->BaseAddress);
        }
        else
        {
            Register = XIo_In8(InstancePtr->BaseAddress +
                               OptionsTable[Index].RegisterOffset);
        }

        /* If the bit in the register which correlates to the option is set,
         * then set the corresponding bit in the options, ignoring any bits
         * which are zero since the options variable is initialized to zero
         */
        if (Register & OptionsTable[Index].Mask)
        {
            Options |= OptionsTable[Index].Option;
        }
    }

    return Options;
}

/****************************************************************************/
/**
*
* Sets the options for the specified driver instance. The options are
* implemented as bit masks such that multiple options may be enabled or
* disabled simultaneously.
*
* The GetOptions function may be called to retrieve the currently enabled
* options. The result is ORed in the desired new settings to be enabled and
* ANDed with the inverse to clear the settings to be disabled. The resulting
* value is then used as the options for the SetOption function call.
*
* @param    InstancePtr is a pointer to the XUartNs550 instance to be worked on.
* @param    Options contains the options to be set which are bit masks
*           contained in the file xuartns550.h and named XUN_OPTION_*.
*
* @return
*
* - XST_SUCCESS if the options were set successfully.
* - XST_UART_CONFIG_ERROR if the options could not be set because the hardware
*   does not support FIFOs
*
* @note
*
* None.
*
*****************************************************************************/
XStatus XUartNs550_SetOptions(XUartNs550 *InstancePtr, Xuint16 Options)
{
    Xuint32 Index;
    Xuint8 Register;

    /*
     * Assert validates the input arguments
     */
    XASSERT_NONVOID(InstancePtr != XNULL);
    XASSERT_NONVOID(InstancePtr->IsReady == XCOMPONENT_IS_READY);

    /*
     * Loop thru the options table to map the logical options to the physical
     * options in the registers of the UART.
     */
    for (Index = 0; Index < XUN_NUM_OPTIONS; Index++)
    {

       /* If the FIFO control register is being read, this is a special case
        * that requires special register processing
        */
        if (OptionsTable[Index].RegisterOffset == XUN_FCR_OFFSET)
        {
            Register = ReadFcrRegister(InstancePtr->BaseAddress);
        }
        else
        {
            /* Read the register which contains option so that the register can
             * be changed without destoying any other bits of the register
             */
            Register = XIo_In8(InstancePtr->BaseAddress +
                               OptionsTable[Index].RegisterOffset);
        }

        /* If the option is set in the input, then set the corresponding bit
         * in the specified register, otherwise clear the bit in the register
         */
        if (Options & OptionsTable[Index].Option)
        {
            Register |= OptionsTable[Index].Mask;
        }
        else
        {
            Register &= ~OptionsTable[Index].Mask;
        }
        /* Write the new value to the register to set the option */

        XIo_Out8(InstancePtr->BaseAddress +
                 OptionsTable[Index].RegisterOffset, Register);
    }

    /* To be done, add error checks for enabling/resetting FIFOs */

    return XST_SUCCESS;
}

/****************************************************************************/
/**
*
* This function gets the receive FIFO trigger level. The receive trigger
* level indicates the number of bytes in the receive FIFO that cause a receive
* data event (interrupt) to be generated.
*
* @param    InstancePtr is a pointer to the XUartNs550 instance to be worked on.
*
* @return
*
* The current receive FIFO trigger level.  Constants which define each trigger
* level are contained in the file xuartns550.h and named XUN_FIFO_TRIGGER_*.
*
* @note
*
* None.
*
*****************************************************************************/
Xuint8 XUartNs550_GetFifoThreshold(XUartNs550 *InstancePtr)
{
    Xuint8 FcrRegister;

    /*
     * Assert validates the input arguments